vm/gce: accept un-tar-ed image

vm/gce differs from other VM types in that it accepts image
in a weird, GCE-specific format (namely, image named disk.raw
is put into .tar.gz file). This makes it impossible to write
generic code that creates images for any VM types.

Make vm/gce accept just image like e.g. vm/qemu
and handle own specifics internally.

3 files changed, 26 insertions, 25 deletions

diff --git a/pkg/gcs/gcs.go b/pkg/gcs/gcs.go
index 0121d2aeb..97883256a 100644
--- a/pkg/gcs/gcs.go
+++ b/pkg/gcs/gcs.go
@@ -80,25 +80,35 @@ func (client *Client) Read(gcsFile string) (*File, error) {
 }
 
 func (client *Client) UploadFile(localFile, gcsFile string) error {
-	bucket, filename, err := split(gcsFile)
+	local, err := os.Open(localFile)
 	if err != nil {
 		return err
 	}
-	local, err := os.Open(localFile)
+	defer local.Close()
+
+	w, err := client.FileWriter(gcsFile)
 	if err != nil {
 		return err
 	}
-	defer local.Close()
-	bkt := client.client.Bucket(bucket)
-	f := bkt.Object(filename)
-	w := f.NewWriter(client.ctx)
 	defer w.Close()
+
 	if _, err := io.Copy(w, local); err != nil {
 		return err
 	}
 	return nil
 }
 
+func (client *Client) FileWriter(gcsFile string) (io.WriteCloser, error) {
+	bucket, filename, err := split(gcsFile)
+	if err != nil {
+		return nil, err
+	}
+	bkt := client.client.Bucket(bucket)
+	f := bkt.Object(filename)
+	w := f.NewWriter(client.ctx)
+	return w, nil
+}
+
 func split(file string) (bucket, filename string, err error) {
 	pos := strings.IndexByte(file, '/')
 	if pos == -1 {
diff --git a/pkg/kernel/generated.go b/pkg/kernel/generated.go
index 0e6ba5b89..e9b00b345 100644
--- a/pkg/kernel/generated.go
+++ b/pkg/kernel/generated.go
@@ -8,17 +8,12 @@ const createImageScript = `#!/bin/bash
 set -eux
 
 if [ ! -e $1/sbin/init ]; then
-	echo "usage: create-gce-image.sh /dir/with/user/space/system /path/to/bzImage /path/to/vmlinux 'image tag'"
+	echo "usage: create-gce-image.sh /dir/with/user/space/system /path/to/bzImage"
 	exit 1
 fi
 
 if [ "$(basename $2)" != "bzImage" ]; then
-	echo "usage: create-gce-image.sh /dir/with/user/space/system /path/to/bzImage /path/to/vmlinux 'image tag'"
-	exit 1
-fi
-
-if [ "$(basename $3)" != "vmlinux" ]; then
-	echo "usage: create-gce-image.sh /dir/with/user/space/system /path/to/bzImage /path/to/vmlinux 'image tag'"
+	echo "usage: create-gce-image.sh /dir/with/user/space/system /path/to/bzImage"
 	exit 1
 fi
 
@@ -75,10 +70,4 @@ sudo grub-install --boot-directory=disk.mnt/boot --no-floppy /dev/nbd0
 sudo umount disk.mnt
 rm -rf disk.mnt
 sudo qemu-nbd -d /dev/nbd0
-tar -Szcf disk.tar.gz disk.raw
-mkdir -p obj
-cp $3 obj/
-echo -n "$4" > tag
-tar -czvf image.tar.gz disk.tar.gz key tag obj/vmlinux
-rm -rf tag obj
 `
diff --git a/pkg/kernel/kernel.go b/pkg/kernel/kernel.go
index 9e9b4b32d..5992900f7 100644
--- a/pkg/kernel/kernel.go
+++ b/pkg/kernel/kernel.go
@@ -60,8 +60,8 @@ func Build(dir, compiler, config string, fullConfig bool) error {
 
 // CreateImage creates a disk image that is suitable for syzkaller.
 // Kernel is taken from kernelDir, userspace system is taken from userspaceDir.
-// The resulting image is marked with tag and copied to the specified image file.
-func CreateImage(kernelDir, userspaceDir, tag, image string) error {
+// Produces image and root ssh key in the specified files.
+func CreateImage(kernelDir, userspaceDir, image, sshkey string) error {
 	tempDir, err := ioutil.TempDir("", "syz-build")
 	if err != nil {
 		return err
@@ -71,12 +71,14 @@ func CreateImage(kernelDir, userspaceDir, tag, image string) error {
 	if err := ioutil.WriteFile(scriptFile, []byte(createImageScript), 0700); err != nil {
 		return fmt.Errorf("failed to write script file: %v", err)
 	}
-	vmlinux := filepath.Join(kernelDir, "vmlinux")
-	bzImage := filepath.Join(kernelDir, "arch/x86/boot/bzImage")
-	if _, err := osutil.RunCmd(time.Hour, tempDir, scriptFile, userspaceDir, bzImage, vmlinux, tag); err != nil {
+	bzImage := filepath.Join(kernelDir, filepath.FromSlash("arch/x86/boot/bzImage"))
+	if _, err := osutil.RunCmd(time.Hour, tempDir, scriptFile, userspaceDir, bzImage); err != nil {
 		return fmt.Errorf("image build failed: %v", err)
 	}
-	if err := os.Rename(filepath.Join(tempDir, "image.tar.gz"), image); err != nil {
+	if err := os.Rename(filepath.Join(tempDir, "disk.raw"), image); err != nil {
+		return err
+	}
+	if err := os.Rename(filepath.Join(tempDir, "key"), sshkey); err != nil {
 		return err
 	}
 	return nil